Water

ImpEEIMPRO

VIN

G

ENG

INEERIN

G

EDU

CA

TION

PROJECT

THE

Total volume of water on Earth (100%) = 1,386,000,000 km3

Total freshwater (2.5%) = 35,029,000 km3

Available freshwater = 200,000 km3

The Blue Planet?

119,000 km3/yr(20%)

458,000 km3/yr(80%)

505,000 km3/yr(88%)

72,000 km3/yr(12%)

Available - 47,000 km3/yr (8%)

Atmospheric water 0.035% of the Earth’s fresh water

Transpiration takes a few hours

Residence time of lakes approximately

10 years

Residence time of oceans approximately 100 years

Residence time of groundwater may be thousands of years

60% of molecules falling as rain are re-evaporated in 1-2 days

Hydrological CycleResidence time in the atmosphere is approximately 1 week

Water Supply

0

20,000

40,000

60,000

80,000

100,000

Austra

lia

Canad

aUSA UK

Mex

ico

Russi

an Fe

dera

tionBr

azil

Albania

China

South

Afric

aInd

iaNep

al

Afghan

istan

Total Freshwater SupplyTotal Freshwater Withdrawal

cubi

c m

etre

s pe

r pe

rson

per

yea

r

The role of engineers

“The engineers that help realise these water supply opportunities will be this century’s most valued peace keepers”

Andrew Mylius

0

625

1,250

1,875

2,500D

enm

ark

Afg

hani

stan

Chi

naG

erm

any

Nig

eria

Iran

Eritr

ea UK

Uzb

ekist

anIn

dia

Mau

ritiu

sM

alaw

iC

omor

osH

aiti

Som

alia

Ethi

opia

Zim

babw

eBu

rkin

a Fa

soRe

p. O

f Kor

eaPo

land

Ant

igua

& B

arbu

daEg

ypt

Belg

ium

Cyp

rus

Sout

h A

fric

aLe

bano

nM

oroc

coKe

nya

Rwan

daC

ape

Verd

eBu

rund

iD

jibou

tiA

lger

iaSt

Kitt

s &

Nev

isTu

nisia

Om

anBa

rbad

osIs

rael

Yem

enJo

rdan

Qat

arBa

hrai

nSi

ngap

ore

Saud

i Ara

bia

Lybi

an A

rab

Jam

ahiri

yaM

aldi

ves

Uni

ted

Ara

b Em

irate

sM

alta

Kuw

ait

Water ScarcityA

nnua

l Ren

ewab

le F

resh

wat

er A

vaila

bilit

y [m

3 /ca

pita

/yea

r]

UK

lack of water begins to hamper economic development and human health and well-being

< 1700m3/capita/yearChronic Water Scarcity

< 1700m3/capita/yearAbsolute Water Scarcity

< 1700m3/capita/yearRegular Water Stress

• If the amount of ground water withdrawn exceeds natural inflow, there is a water debt

• In such cases, water should be considered as a non-renewable resource that is being mined.

Water debt

Water debt

-15

-10

-5

0

5

Kuwait UAE

Libya

Saud

i Ara

biaM

alta

Qatar

Bahra

inOman

Total Freshwater Supply [km³/year]Water Debt

cubi

c ki

lom

etre

s pe

r ye

ar

• Seawater contains about 3.5% salt

• One cubic meter of sea water contains around 40kg of salt

• To produce ‘freshwater’ the salt content must be reduced to less than 0.05%

Desalination

Desalination

Mem

bran

e fil

ter

1.8 units of seawater

1 unit freshwater

0.8 unitswastewater

Sea water pumped through at a pressure

of approximately 7,000 bar

Increasing Global Use

0

1,375

2,750

4,125

5,500

1900 1920 1940 1960 1980 2000

Domestic Use Industrial UseAgricultural Use Total Use

km3

per

year

Global Freshwater Use

10%

25%

65%

AgriculturalIndustrialDomestic

Data from 1992

Water Use

0

500

1,000

1,500

2,000

Austra

lia

Canad

aUSA UK

Mex

ico

Russi

an Fe

d.Br

azil

Albania

Chinea

South

Afric

aInd

iaNep

al

Afghan

istan

Domestic IndustrialAgricultural

m3

per

pers

on p

er y

ear

Agriculture

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

45,000

Potatoes Sugar Beet Maize Wheat Rice Chicken Beef

Qua

ntity

of W

ater

[litr

es/k

g]

It takes nine times as much water to produce 1kg of beef compared to that

required to produce 1kg of chicken

Scale 10 x Manufacturing

Use chart

Per 1kg

Manufacturing

0

500

1,000

1,500

2,000

2,500

3,000

3,500

4,000

4,500

Bricks BeerRefinedCrude Oil Paper Steel Fertiliser Aluminium

SyntheticRubber

Qua

ntity

of W

ater

[litr

es/k

g]

Scale 0.1 x Agricultural Use chart

Per 1kg or 1l

State of RiversState of Rivers

State of UK Rivers

60%

70%

80%

90%

100%

1995 1996 1997 1998 1999 2000 2001 2002 2003 2004

North West Southern South West Thames England and Wales

Perc

enta

ge o

f tot

al r

iver

leng

th c

ompl

ying

w

ith r

iver

eco

syst

em o

bjec

tives

Dry Summers, such as in 2003, lead to low river flow and concentration of pollutants in remaining water

Dry Summers experienced in particular in South East of England

WC FlushingBath / ShowerDishwasherDrinkingWashing MachineOutsideMiscellaneous

UK domestic water use

9% 6%14%

8%

8%

20%

35%

Potable quality water required only for those applications

indicated – approximately one third of total domestic use

Things to think aboutSociety demands

cleaner rivers

More global warming emissions

River quality decreases

More treatment

Increased energy use

Less dilution for effluents

VICIOUS CIRCLE

Energy costs of stricter water treatment legislation

•Water Industry and Global Water•The Paradox of treating all water to a fully potable standard

Tighter effluent standards

Drier Summers

Early SettlementsBuilt on high ground above rivers

Key buildings such as churches protected from flooding

Recent DevelopmentsExpansion onto flood plain

Key buildings such as hospitals at risk of flooding

Population growth and increasing urbanisation, coupled with paving over of more land leads to less surface water infiltration, higher peak flow after storms

and increased frequency and severity of flood events

Flooding

Dublin PrinciplesPrinciple No. 1: Fresh water is a finite and vulnerable resource, essential to sustain life, development and the environment.

Principle No. 2:Water development and management should be based on a participatory approach, involving users, planners and policy-makers at all levels.

Principle No. 3: Women play a central part in the provision, management and safeguarding of water.

Principle No. 4: Water has an economic value in all its competing uses and should be recognised as an economic good.

HydropoliticsControl of Water Resources: Water supplies or access to water at the root of tensions

Military Tool: Water resources, or water systems themselves, used by a nation or state as a weapon during military action

Political Tool: Water resources, or water systems themselves, used by a nation, state or non-state actors for a political goal

Terrorism: Water resources, or water systems, as targets or tools of violence or coercion by non-state actor

Military Target: Water resource systems as targets of military actions by nations or states

Development Disputes: Water resources or systems as source of contention in the context of social and economic development

ImpEE is based at the Department of Engineering at the University of Cambridge and is funded by the CMI Institute.

© University of Cambridge, 2006

This material was produced as a part of the ImpEE Project at the University of Cambridge. It may be reproduced, modified and used freely for

educational purposes.